Remember!

1. Remember! • Charles Darwin’s theory on evolution is called Natural Selection. • Darwin’s ideas have been proven by many studies & the theory of natural selection is widely accepted!

2. A quick simulation of evolution… • Peppered moths in the industrial evolution • http://www.utdanacenter.org/texteams/downloads/scienceresources/pradeep_fla.swf

3. Natural Selection

4. What is Natural Selection & how does it drive Evolution?

5. Variation Within a Species • Different organisms within a species have differences in morphology & physiology! • Morphology: the form or shape of an organism • Physiology: the mechanical, physical, & biochemical functions of living organisms Morphology Physiology

6. Physiology – some of us have a fast metabolism, while some of us have a slow metabolism! Morphology – some of us are tall, while some of us are short!

7. Variation Within a Species • These differences change the ability of an organism to survive & reproduce. This is called an organism’s fitness! Some bears can dive deep into the water to catch salmon, but some can’t. Which bears do you expect to survive better?

8. Adaptation • Any inherited characteristic that increases an organism’s chance of survival & ability to reproduce Monarch Butterflies are poisonous to eat & they have special coloration to warn predators.

9. Fitness & Adaptations • Those individuals that are better able to survive & reproduce (have a higher fitness) pass on their morphological & physiological differences to their offspring!

10. Selective Pressure • Over time, populations are changed based on selective pressures of the environment. • Selective Pressure: any factor that makes it hard for some organisms to continue surviving, & rewards any advantage that some organisms may have been born with

11. Selective Pressures • Climate Changes • Food Supply Changes • Predators • Sexual Selection What was the selective pressure in your dot experiment?

12. Antibiotic Resistance What’s the selective pressure driving this population to evolve?

13. Let’s break it down… • Organisms produce more offspring than can possibly survive! • Those that do not survive do not reproduce, & therefore do not pass down their genes. • Each organism has different advantages & disadvantages in the struggle for existence. • Individuals best suited for their environment survive & reproduce most successfully.

14. Evolution by Means of Natural Selection • Natural Selection – “Survival of the Fittest” • Adaptations can be morphological, behavioral, or physiological, but they are NOT learned! • Adaptations may be an advantage in 1 environment & a disadvantage in another! • Natural Selection • Only acts on heritable traits • Does not form NEW characteristics (only mutations can do that) • Is backward looking, not planned or perfect • Acts on the individual, but the effect is on the population!

15. Charles Darwin’s Theory of Evolution • Darwin published Origin of Species in 1859, which was 23 years after his journey around the world. What took him so long? • Darwin was scared to publish his findings, because society wasn’t ready for it! • Darwin’s theories went against religious beliefs. • He also proved that ALL men are closely related to primates (racism ruled society & many believed that black people were related to monkeys, but not white people!).

16. Charles Darwin’s Theory of Evolution • Darwin finally decided to publish, because he heard that someone else was publishing work that shared the same theories! • Alfred Wallace: in 1858, wrote a paper on NS almost identical to Darwin’s • Why have you never heard of him?

17. Charles Darwin’s Theory of Evolution • Darwin’s work was unpopular with the religious & racist society. • There are still people today who do not accept evolution as fact. • The modern theory of evolution unites the work of Darwin & Mendel. • Incorporates population genetics, behavior, ecology, paleontology, phylogeny, etc.